➤HYDRATION SYSTEM COMPATIBLE ---- Hydration access on a side of the travel backpack with water bladder sleeve in the main compartment.HYDRATION BLADDER COMPARTMENT: There is a compartment in the main pocket designed for putting Hydration Bladder, keeping you hydrated for a day when you are in various sports activities, such as climbing, hiking, camping, backpacking, traveling,etc. Hydration Bladder is NOT INCLUDED